Percentage of users or customers who keep using the product
Retention is the percentage of customers or users who continue engaging with a product over a given time period. It's the inverse of churn and the foundation of healthy SaaS unit economics. Strong retention compounds into NRR above 100%.
A product with 95% monthly retention retains ~54% of users after 12 months. At 90% monthly retention, that drops to ~28% — compounding makes every percentage point critical.